ARM, CUBITAL FOSSA & ELBOW JOINT
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Transcript of ARM, CUBITAL FOSSA & ELBOW JOINT
Khaleel Alyahya, PhD, MEd Zeenat Zaidi, MD, PhD
ARM, CUBITAL FOSSA & ELBOW JOINT
OBJECTIVES At the end of the lecture, students should: Describe the attachments, actions and innervations of:
Biceps brachii Coracobrachialis Brachialis Triceps brachii
Demonstrate the following features of the elbow joint: Articulating bones Capsule Lateral & medial collateral ligaments Synovial membrane
Demonstrate the movements; flexion and extension of the elbow. List the main muscles producing the above movements. Define the boundaries of the cubital fossa and enumerate its contents.
The ARM
Anteriorview
Posteriorview
Shoulder
Elbow
HumerusArm
A
R
M
The ARM
The lateral and medial intermuscular septa divide the distal part of the arm into two compartments: Anterior Posterior
Medial intermuscular
septum
Humerus
Fascia
skin
Lateral intermuscular
septum
Neurovascular bundle
Muscles: Biceps brachii, Coracobrachialis &Brachialis.Blood Vessels: Brachial artery & Basilic vein.Nerves : Musculocutaneous, Median, Radial & Ulnar.
Anterior Fascial Compartment Contents
Muscles of the Anterior Compartment
Biceps brachii
Coracobrachialis
Brachialis
Origin: Two heads: Long Head from supraglenoid tubercle of scapula (intracapsular) Short Head from the tip of coracoid process of scapula
The two heads join in the middle of the arm
Biceps BrachiiCoracoid Process
Insertion: in the posterior part of the radial
tuberosity.into the deep fascia of the medial
aspect of the forearm through bicipital aponeurosis.
Nerve supply: Musculocutaneous
Action: Strong supinator of the forearm
used in screwing.Powerful flexor of elbowWeak flexor of shoulder
Biceps BrachiiBiceps brachii
Bicipitalaponeurosis
Tendon inserted to radial tuberosity
Origin: Tip of the coracoid process
Insertion: Middle of the medial side of the shaft of the humerus
Nerve supply: Musculocutaneous
Action: Flexor & a weak adductor of the arm
Coracobrachialis
Origin: Front of the lower half of humerus
Insertion: Anterior surface of coronoid process of ulna
Nerve supply: Musculocutaneous & Radial
Action: Strong flexor of the forearm
Brachialis
Muscles: Triceps Vessels: Profunda brachii & Ulnar collateral arteries Nerves: Radial & Ulnar
Posterior Fascial Compartment Contents
Muscles of the Posterior Compartment
Triceps brachii
Origin: Three heads: Long Head from infrglenoid tubercle of the scapula Lateral Head from the upper half of the posterior surface of the shaft of humerus above the spiral groove Medial Head from the lower half of the posterior surface of the shaft of humerus below the spiral groove
Triceps
Insertion: Common tendon inserted into the upper surface of the olecranon process of ulna
Nerve supply: Radial nerve
Action: Strong extensor of the elbow joint
Triceps
The cubital fossa is a triangular depression that lies in front of the elbow
Cubital Fossa
Base: Line drawn through the two epicondyles of humerus
Laterally: Brachioradialis
Medially: Pronator teres
Roof: Skin, superficial & deep fascia and bicipital aponeurosis
Floor: Brachialis medially and supinator laterally.
Boundaries of Cubital Fossa
Brachioradialis Pronator teres
Content of Cubital Fossa
1. Median nerve
2. Brachial arterydivides into radial & ulnar arteries.
3. Biceps brachii tendon
4. Deep branch of radial nerve
(From medial to lateral side)
Radial arteryUlnar artery
Articulation Trochlea and capitulum of the
humerus above
Trochlear notch of ulna and the head of radius below
ELBOW JointUniaxial, Synovial Hinge joint
The articular surfaces are covered with articular (hyaline) cartilage.
ELBOW Joint
Trochlea
Capitulum
Anteriorly: attached Above
To the humerus along the upper margins of the coronoid and radial fossa and to the front of the medial and lateral epicondyles.
Below To the margin of the coronoid process of the ulna and to the anular ligament, which surrounds the head of the radius.
Capsule
Posteriorly: attached Above
To the margins of the olecranon fossa of the humerus.
Below To the upper margin and sides of the olecranon process of the ulna and to the anular ligament.
Capsule
Triangular in shape:Apex
Attached to the lateral epicondyle of humerus
Base Attached to the upper
margin of annular ligament.
LigamentsLateral (radial collateral) ligament
Anterior strong cord-like band: Between medial epicondyle and the coronoid process of ulna
Posterior weaker fan-like band: Between medial epicondyle and the olecranon process of ulna
Transverse band: Passes between the anterior and posterior bands
LigamentsMedial (ulnar collateral) ligament
This lines the capsule and covers fatty pads in the floors of the coronoid, radial, and olecranon fossa.
Is continuous below with synovial membrane of the superior radioulnar joint
Synovial Membrane
Anterior: Brachialis, tendon of biceps,
median nerve, brachial artery
Posterior: Triceps muscle, small bursa
interveningLateral:
Common extensor tendon & the supinator
Medial: Ulnar nerve
Considered the largest unprotected nerve in the human body by muscle or bone,
Relations
Bursae around the elbow joint: Subcutaneous olecranon bursa Subtendinous olecranon bursa
Flexion Is limited by the anterior surfaces
of the forearm and arm coming into contact.
Extension Is limited by the tension of the
anterior ligament and the brachialis muscle.
The joint is supplied by branches from the: Median Ulnar Musculocutaneous Radial nerves
Movements
Angle Between the long axis of the extended forearm and the long axis of the arm
Opens Laterally
About 170 degrees in male and 167 degrees in females
Disappears When the elbow joint is flexed
Permits The forearms to clear the hips in swinging movements during walking, and is important when carrying objects
Carrying Angle
1650-1700
The elbow joint is stable because of the: Wrench-shaped articular surface of the olecranon and the pulley-shaped trochlea of the humerus Strong medial and lateral ligaments.
Elbow dislocations are common & most are posterior.
Posterior dislocation usually follows falling on the outstretched hand. Posterior dislocations of the joint are common in children because the parts of the bones that stabilize the joint are incompletely developed.
Articulations
Avulsion of the epiphysis of the medial epicondyle is also common in childhood because then the medial ligament is much stronger than the bond of union between the epiphysis and the diaphysis.
ELBOW Joint
QUEST!ONS?